The present invention relates generally to a pivot apparatus including a fastener and bushing assembly for pivotally connecting pivotable members such as for reclinable seat assemblies and the like.
With regard to such seat assemblies, the fastener and bushing assemblies of the pivot apparatus of the present invention are mountable within aligned openings of pivot plates or brackets to inhibit metal to metal engagement which could cause wear and undesirable noise such as squeaking and rattling.
Typically, reclinable seat assemblies have a seat bottom and a seat back pivotable from between selected upright and reclined positions relative to the seat bottom. A releasable latch type mechanism is provided for selectively maintaining the seat back in the upright or one or more reclined positions. The seat bottom and seat back have pivot members such as plates or brackets mounted thereon with each of such pivot members having at least one opening formed therein. The opening in the seat back pivot member is generally a smooth hole while the seat bottom pivot member opening is generally a threaded hole; the openings are alignable for receiving a fastener such as a threaded bolt or the like. Upon release of the latch mechanism, the seat back can be pivoted about the bolt relative to the seat bottom between reclined and upright positions.
Previously, the bolt or the like was inserted into the aligned openings and the seat back pivot member was pivotally supported upon the bolt with direct metal to metal engagement. Subsequent improvements provided a non-metallic bushing to be mounted about the bolt and within the opening of the pivot member of the seat back to allow it to pivot smoothly about the bolt mounted bushing. While assisting in maintaining a generally smooth and even reclinability of the seat back such assemblies could require additional components to provide wear resistance and noise insulation. Such assemblies would not necessarily maintain complete separation and inhibit axial movement between the pivot members which could result in wear of the bushing and/or engagement of the pivot members. In addition such assemblies could require multiple assembly steps.
In one such improvement a non-metallic bushing is provided with an outer end which extends through an opening in one or more members and is adapted to be upset or flipped radially outwardly by a special tool whereby it would be self-retaining and locked to the one or more members. See in this regard U.S. Pat. No. 4,363,580 issued Dec. 14, 1982 for "Self-Retaining Close Tolerance Bushing". Where such bushings are to be used as pivot apparatus, the associated bolt would be inserted into the bushing after the upsetting step.
Thus it would be advantageous to provide a pivot apparatus including a fastener and a bushing in which the bushing provides a structure which can be installed in assembly with an associated bolt to members for pivotal movement and thus does not require a separate step to install the bolt to provide the final assembly.
In this regard it would also be advantageous to provide such a pivot apparatus in which the bushing would automatically locate and resiliently hold itself in a desired position relative to the members to be pivotally secured.
It would be advantageous to provide a pivot apparatus including a fastener and bushing assembly which minimizes wear, noise and degradation to the bushing. It would also be advantageous to provide a fastener and bushing assembly which is easy to manufacture and install with minimum installation steps. At the same time it would be advantageous to provide a bushing which when fixed with the mating bolt would resiliently maintain the pivotal members in a desired spaced relationship while permitting the desired pivotal action.
The pivot apparatus of the present invention addresses the preceding objectives. Thus the fastener and bushing assembly of the present invention comprises a bolt like fastener having a longitudinal axis and a resilient, cylindrical bushing frictionally mounted about the fastener with the bushing having an inner pivot support portion and an outer resilient spacer portion. The outer spacer portion of the bushing is formed with at least one axially extending slot wherein upon mounting the bolt and bushing assembly within the aligned openings of the first and second pivot members, the outer end of the bushing upon engaging a surface of one of the pivot members will be flared radially outwardly from the longitudinal axis of the bolt and between the first and second pivot members to provide a resiliently variable length of the bushing to compensate for tolerance variations in the axial distance or spacing between the pivot members. At the same time the flared outer end wall resiliently inhibits relative axial movement of the bushing and movement between the pivot members while resiliently maintaining them spaced from contact with each other.
In the present invention, the bushing has a main bushing support portion extending from a flanged inner end of the bushing and a resilient, bushing spacer portion at the outer end of the bushing. In one form of the invention, the main bushing portion has an outer diameter greater than the outer diameter of the extended bushing spacer portion.
In one form of the present invention, a pair of diametrically opposite axial slots are formed in the bushing spacer portion to define a pair of finger like sections. Each slot terminates at the outer end in a first slot side and a second slot side. In this embodiment the outer edge of the finger like sections extends circumferentially somewhat helically inwardly from the first slot side of one slot to the second slot side of the other slot. Thus the edge at the first slot sides extends axially farther than the edge at the second slot side. As will be seen, in this way, in installation, the edges at the first slot sides will engage the confronting surface on the pivot member before the edge at the second slot sides thereby facilitating the radial outward flaring of the finger like sections. This results in the formation of a flared end surface in smooth, resilient contact with the engaged surface of the related pivot member to thereby restrain relative axial movement of the bushing and of the pivot members towards each other. At the same time the flared end surface provides a means to resiliently compensate for dimensional tolerance variations in the spacing between the pivot members while automatically positioning and securing the bushing in the desired location. At the same time this is accomplished with little variation in the magnitude of the installation load. Preferably, the slots extend substantially parallelly to the longitudinal axis of the fastener and are of a length to permit the desired flaring.
It should be understood that the bushing could have a single slot or more than two slots formed therein.
In one form of the present invention, the fastening assembly comprises a plurality of axially extending, resilient ribs formed along the outer surface of the main bushing portion with at least a part of the ribs having an outer diameter greater than the diameter of the associated one of aligned openings. Preferably, the plurality of ribs are equally circumferentially spaced. The ribs are elastically deformable upon insertion into the associated opening to thereby compensate for dimensional variations while providing a relatively snug fit.
In one form of the present invention, the bushing is constructed from a resilient thermoplastic material. Thus when the ribs are under compression, the material comprising the ribs is deformable to an area between the ribs absorbing any manufacturing tolerances within the openings to provide a relatively snug fit.
In one form of the present invention the bushing and bolt are constructed to pivotally support two pivot members comprising a single plate each while in other forms the bushing and bolt are constructed to pivotally support two pivot members comprising multiple, spaced plates.
Furthermore in another feature of the present invention, the bushing maintains relative longitudinal positioning with the fastener upon mounting of the bushing onto the fastener and the bushing withstands at least a three (3 lb.) pound static load applied to either the bushing or the fastener in a longitudinal direction to facilitate handling prior to and during installation and to inhibit relative rotation after installation.
The present invention further includes a method for pivotally fastening a first pivot member to a second pivot member with a fastener and bushing assembly of the type of the present invention. The first and second members have alignable apertures therethrough with the aligned apertures adapted to receive the fastener and bushing assembly whereby the pivot members are supported for pivotal movement relative to each other.
The method of the present invention comprises providing a fastener having a longitudinal axis and a bushing having an inner portion and an outer portion. The bushing is tightly mounted on the fastener. At least one axial slot is formed in the bushing extending inwardly from the outer end of the bushing. The fastener and bushing assembly is mounted within aligned openings of first and second pivot members. The method comprises forming the outer end of the bushing to be self-flaring generally radially outwardly from the longitudinal axis of the fastener upon engagement with one of the pivot members and between the first and the second pivot members thereby resiliently inhibiting relative axial movement of the bushing and between the first and second members while permitting relative rotation between the pivot members.
The method further comprises providing a bushing with one or more slots each having a first slot side and a second slot side, and providing an outer circumferential edge at the outer end of the bushing from the first slot side to the second slot side which extends generally helically whereby the first slot side will have an axial length greater than that of the second slot side to facilitate flaring upon installation.
Another feature of the method of the present invention is providing a fastener and bushing assembly which maintains relative axial positioning between the bushing and the fastener upon mounting of the bushing onto the fastener such that the bushing can withstand at least a three (3 lb.) pound static load applied to either the bushing or the fastener in an axial direction while maintaining such positioning whereby handling of the assembly prior to and during installation is facilitated and relative rotation therebetween is inhibited.
Therefore, it is an object of the present invention to provide a fastener and bushing assembly for pivotally supporting a pair of pivot members while maintaining axial spacing or separation between the pivot members.
It is another object of the present invention to provide such a fastener and bushing assembly in which the bushing has a deformable portion which upon assembly deforms to provide a structure for maintaining axial spacing between the pivot members.
It is an object of the present invention to provide such a fastener and bushing assembly in which the bushing has a deformable portion which upon assembly deforms to provide a resilient structure for compensating for dimensional tolerance variations in the spacing between pivot members.
It is still another object of the present invention to provide a method of pivotally securing two members together whereby the axial spacing between the pivot members is resiliently maintained and engagement of the pivot members is inhibited.
It is another object of the present invention to provide a method of pivotally securing two members together with minimal installation steps.
It is a general object of the present invention to provide a unique assembly for pivotally securing two members together.
Other objects, features, and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, in which: